Dot matrix print heads are used in electric printers and produce mosaic-like symbols that are compiled from printed dots produced by several printing pins. The quality of the symbols depends on the number of printing pins and/or on the frequency of their activation. The more printing pins are contained in a dot matrix print head, the better the ability of the printing dots to produce a symbol and the better the ability to read the same.
A dot matrix print head should contain the highest possible number of printing pins. In addition to this it should work at high speed and execute the movement of the printing pins with the highest possible impact, so that duplicates in the form of carbon copies can be produced during the printing process. These demands should also be fulfilled during long term use, which means that the dot matrix print head should have a high continuous output.
It has thus far not been possible to fulfill simultaneously the demands set for a dot matrix print head, which are high printing speeds, high impact and high continuous output. The main reason for this fact is the heat produced by the electromagnetic drive mechanisms for the printing pins, because one proceeded from the premise that a high activation frequency of a printing pin and a high impact force can only be obtained with strong energizing currents and/or a high number of ampere turns in large ferromagnetic circuits. A dot matrix print head constructed according to this principle has very high magnetic frame limbs with a large number of drive mechanisms in order to realize the large volume of iron and the large number of ampere turns. This fact was thus far predetermined by a circular arrangement of the drive mechanisms with printing pins that are arranged in the area of the center of the circle.